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A/C not working

Fri Jul 07, 2017 5:34 am

Hey guys,
The A/C on my 88 ST165 isn't blowing cold anymore.
It was fine 2 months ago but I've had it off the road and when I fired it up today I could tell the A/C wasn't as cold as it should be. What do you guys do to fix the old R12 A/C systems?
Thanks for any advice!
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Re: A/C not working

Fri Jul 07, 2017 5:04 pm

Is the A/C unit not blowing cold air, or is the compressor not turning on? Is the A/C light on the A/C button on? If the A/C light does not come on, you could be low on refrigerant. Unfortunately R12 is hard to come by. You can check local A/C places to see if someone might still have some around. They will need to extract remaining refrigerant and pull a vacuum to test the A/C system for leaks. If all checks out, then they can refill the system. If not, then they will need to repair the system. At this point I would probably have them convert the system to the newer R134 system.

Re: A/C not working

Sat Jul 08, 2017 5:37 am

Finding r12 is pretty tough these days. R134 conversions aren't too difficult diy projects. Depends on how much work and money you want to put into working A/C. Also what tools you have access to. I bought a harbor freight refrigerant gauge set(do not recommend) and have access to a vacuum pump through work. Got my non functional a/c up and running in 2 weekends after god knows how many years. (actually got it running week 1 for about 30 seconds before a 25 year old hose blew up in my face :pissed: )

Re: A/C not working

Sun Aug 13, 2017 10:02 pm

ST185 owner here who JUST got a long dead A/C system fixed.

Depending on where you are, an r134a conversion is going to be either recommended or necessary. The fitting conversion fro what I understand isn't hard, and my local shop did it for me for about $100 all told. However since your system isn't working properly you'll have other things to fix too, and it can quickly cascade into a much larger project in hunting down and fixing leaks after the conversion. To do it 100% proper you should really replace *all* of the O-ring seals in the system with r134 seals, although some shops will offer to try and do the conversion without (as mine did). In my case after doing the r134 conversion and replacing a couple seals and a hose, they found a slow leak on the compressor itself, which is not an obtainable part. It was patched with silicon gasket maker and seems to be holding a charge now.

Good luck.

Re: A/C not working

Sun Aug 13, 2017 11:35 pm

I bought a new ac compressor last year from Walmart.com of all places. I found the denso part number and google searched it.

Went back through my emails.

One warning of converting to r134a, you can't use PAG oil since r12 isn't compatible from what I've read. If you diy use ester oil. Can buy it from autozone.

Denso 471-1238 New Compressor with Clutch https://www.amazon.com/dp/B001UC7O4W/re ... KzbW5PD1A4

Amazon seems cheapest right now.

Edit. That came out wrong. Any oil that's left in the system from r12 isnt compatible with pag oil so its recommended to use ester oil since that will mix with whatever is left in the system.

Re: A/C not working

Tue Oct 03, 2017 9:20 pm

Thanks for the replies guys. Unfortunately, I haven;t been able to look into it more cuz something in my life took a wrong turn and has occupied all my time. I'll repost once it hopefully settles down... :(
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